xanthan gum

Xanthan gum is a polysaccharide produced through bacterial fermentation of glucose or sucrose by the gram-negative bacterium Xanthomonas campestris. The fermentation process yields a viscous broth that is precipitated with isopropyl alcohol, dried, and ground into a fine powder. Chemically, it is a complex polymer composed of glucose, mannose, and glucuronic acid, characterized by a branched structure that imparts unique thickening and stabilizing properties. The molecular architecture allows xanthan gum to function at extremely low concentrations—typically 0.1–1% by weight—making it one of the most efficient thickening agents available in culinary and industrial applications.

In appearance, xanthan gum is an off-white to pale yellow powder with a slightly granular texture. It is readily soluble in both hot and cold water, producing highly viscous solutions without requiring heat or cooking. The resulting gels exhibit pseudoplastic behavior, meaning they thin under shear stress (becoming less viscous when stirred) but regain thickness when at rest.

Xanthan gum is employed as a thickener, emulsifier, and stabilizer across gluten-free baking, sauces, dressings, and modernist cuisine. In gluten-free breads and pastries, it replicates the elasticity and structural support that gluten provides, preventing crumbly texture and promoting moisture retention. It is also used in salad dressings, vinaigrettes, and sauces to maintain uniform consistency and prevent separation of ingredients. In liquid preparations such as soups, gravies, and puddings, xanthan gum creates body and mouthfeel without cloudiness. Modernist chefs employ it to craft spheres, foams, and gels. Typical usage is 0.1–0.5% by weight, depending on desired viscosity; approximately 1 teaspoon (5 grams) thickens 1 cup (240 milliliters) of liquid to a light sauce consistency.